A lighting relay panel may receive control signals from various lighting controls or user interface devices. In addition, the lighting relay panel may direct the received signals to various components within the lighting relay panel (such as relays, microcontrollers, or signal filtering circuits), or to components external to the relay panel (such as additional lighting control devices or lighting fixtures). In some cases, the lighting relay panel may include additional components related to safety and reliability, such as a surge protector, a filter, a brownout detection circuit, or other suitable components.
In some cases, the lighting relay panel provides functions related to safety, circuit protection, control signal and electrical integrity, reliability, and analog or digital control of lighting fixtures. It is desirable for a lighting relay panel to provide such functions reliably, and at a relatively low cost.
In some cases, a lighting relay panel is tested to determine its performance or safety under high-voltage or high-current power events. Designing an AC-powered device, such as a power supply, that can withstand high-voltage transients and surges is a challenge. One technique that has been used involves adding protective devices to the front end. The protective devices may include varistors (e.g., metal oxide varistors), transient voltage suppressors, gas discharge tube suppressors, spark gaps, or other suitable techniques or devices. The selection of the protective devices, as well as the design of the circuits that include the protective devices, need to be capable of passing applicable surge tests and dielectric voltage-withstand tests (e.g., “high potential” or “hipot” tests). A surge test evaluates a product's ability to withstand high voltage or current transient spikes. For example, a surge test may test a product's ability to withstand a 6 kV, 3 kA voltage and current combination waveform caused by a lighting event. A hipot or dielectric voltage withstand test evaluates a product's ability to withstand a high voltage (50/60 Hz or DC) voltage applied between line voltage (hot and/or neutral, L1/L2) and earth ground. It may be desirable for a power supply to include a protection circuit that is capable of withstanding one or both of a hipot test and a surge test.
In a conventional relay panel, relays with different actuation currents or that are connected to different phases of a power signal may have actuations that are staggered over time. However, staggering the relay actuations may slow a response time when multiple relays are being actuated. Therefore, it is desirable to synchronize actuation of multiple relays, including relays that are connected to different phases of a power signal. In some conventional systems, multiple relays are actuated using separate actuation circuits for each relay. However, the separate actuation circuits require increased space (e.g., on a printed circuit board) and cost for the components in the multiple actuation circuits. Therefore, it is also desirable to develop a circuit that is capable of sensing relay actuation for multiple relays, and further capable of actuating multiple relays synchronously.
It may be desirable for each relay connected to a relay control board to have an address that is unique compared to other relays that are included in the lighting relay panel. Assigning unique addresses to relays included in a lighting relay panel may improve reliability of the panel's operation, such as by providing signals (such as configuration, control, or power signals) to only the relay(s) to which the signals are addressed. In addition, it may be desirable for the addresses of relays included in a lighting relay panel to be automatically determined, such as by a microcontroller on a relay control board. Automatic addressing of relays in a panel may reduce the time related to installation and configuration of the lighting relay panel, and may reduce sources of user frustration or user errors.
Existing techniques for 0-10V dimming include providing a reference voltage and an isolated control signal. In some conventional systems, a reference voltage is generated by a single-transistor optocoupler or a digital-to-analog convertor. However, the single-transistor optocoupler may generate varying voltage levels (e.g., “ripple” voltage) on the reference voltage, resulting in the reference voltage varying over time. In addition, the digital-to-analog converter may have a relatively high cost, leading to an overall increase in expense for this existing technique.
Existing techniques for providing power or control signals to lighting system components may include using one or more electrically held relays. An electrically held relay may return to a known state if the power is interrupted, according to the type of electrically held relay used (e.g., normally open, normally closed, momentary operation). The electrically held relays may be installed in the panel, such as during manufacturing. However, the type of electrically held relay that is installed may be inappropriate for some uses, and a user may wish to configure (or reconfigure) a use of the relay after the panel is installed in a lighting system at a premises. It may be advantageous for the relays to be configurable by the user, such as during or after installation of the relay panel at a premises. In addition, it may be advantageous for the relays to be configurable via a configuration signal, such as from a microcontroller, to enable configuration without physically replacing a type of relay.